Ideally, you'd never use AceGUI-3.0 directly. Instead, you'd use AceConfigDialog-3.0 which uses AceGUI-3.0 internally, and was specifically designed for handling options tables.
one thing i have found a use for AceGUI directly is if i need a dynamic list of widgets in a scrollframe. Thats what i do in YssBossLoot. I made a AceGUI widget for loot items (has a place for and items name, texture, type, drop rate) then i make 1-4 container frames (depending on how many difficulty's a dungeon has) this container i fill with a AceGUI Scrollframe, then i simply add all the items to the scrollframe which takes care of the layout for me thus saving me from needing to write all the scrollframe and layout code. once i close it i release all the widgets inside the scrollframe and they will get reused the next time its opened (again here i saved myself some frame recycling code)
other than that your probably better of creating your own GUI (this way you don't have to try to wrap your head around the inner workings of AceGUI)
just remember whatever you do frames can not be destroyed so reuse them as much as possible (and NEVER create new frames OnUpdate)